Change power button logic due to HW change

micropython/modules/opencube_brick/buttons.c

@@ -37,7 +37,7 @@ STATIC void buttons_print(const mp_print_t *print, mp_obj_t self_in, mp_print_ki
 STATIC mp_obj_t buttons_pressed(mp_obj_t self_in) {
     uint16_t pcf_last_read = PCF8575_read_value();
     mp_obj_t tuple[6] = {
-            tuple[0] = mp_obj_new_bool((pcf_last_read & (1u << BUTTON_POWER_RPIN)) != 0),
+            tuple[0] = mp_obj_new_bool((pcf_last_read & (1u << BUTTON_POWER_RPIN)) == 0),
             tuple[1] = mp_obj_new_bool((pcf_last_read & (1u << BUTTON_LEFT_RPIN)) == 0),
             tuple[2] = mp_obj_new_bool((pcf_last_read & (1u << BUTTON_RIGHT_RPIN)) == 0),
             tuple[3] = mp_obj_new_bool((pcf_last_read & (1u << BUTTON_OK_RPIN)) == 0),